Train Your Brain With This Simple Exercise

A one-question brain teaser to sharpen your mental acuity

Posted Feb 11, 2012

Interested in a quick and easy way to test your practical logical skills? Maybe not. What if you learned that this simple test could help you save money, pass an important exam, or give you better ways to fix something that's broken? Perhaps that logic test might be worth checking out.

Here's the basic problem.  You have in front of you the 4 cards you see here, face up, showing: A D 2 7.  Each of them has a letter on one side and a digit on the other. Given the rule "If a card has a vowel on one side, then it has an even number on the other side", which cards would you need to turn over to allow you to determine whether the rule is true? 

Did you guess A only, or A and 2? The large majority of people in fact pick A and 2. Before I reveal whether you're right or not, let me go on to a similar problem framed in more concrete terms.

Imagine you're a bouncer at a bar where the legal drinking age is 21. In order to buy an alcoholic beverage, customers must present a card showing their age which shows on the reverse side whether they can buy an alcoholic drink or not. 

The 4 cards you inspect show: "Beer" "Coke" "23" "17"

Before opening for the evening, you're inspecting these four tickets, which are a sample of the ones you'll be selling.   To make sure they're valid, which card or cards must you turn over?

Did you say Beer and 23? Or did you say Beer and 17? Why would you pick 17?  If you're a bouncer, you know that many people use fake ID's. That card that says the person's age is 17 sure better say "Coke" and not "Beer" or there are going to be a lot of inebriated teens at your establishment.

By now you may have guessed that the right answer to the first question was A and 7, not A and 2. If the 7 has a A on the other side, then the rule has been violated. It's possible that the rule isn't violated, either, but if you only turn over one card (the A) or fail to turn over the other (the 7), you'll never know.  

It's typical for adults to get the right answer to the bouncer problem but not to the A-7 question. The A-7 is the abstract version of the problem and the bouncer is the concrete, more easily relatable, version. There are a number of other forms of this problem, known as the "Wason Selection Test," developed by British psychologist Peter Wason as a way to understand why ordinary, mature, rational adults are prone to simple logical blunders.

As I've discussed in an earlier blog, adults aren't always the best problem-solvers, even when it comes to tasks that a third-grader is supposed to be able to master.  We are easily.  Studying the illogical features of the human mind is what makes psychology so fascinating. Unfortunately, these illogical features can get us in trouble.

Just as we sometimes need to count on our fingers to solve problems we should be able to do in our heads (e.g. how many days are there between Tuesday and Saturday?) the Wason task in the A-7 version baffles us because it isn't a problem we encounter in real life.  We are more likely to run into problems such as the bouncer's but, even then, people have a preference to forget that they need to flip over the card that says 17.  It's as if we're primed to seek confirmation of our hunches, but hate finding out that our hunch is wrong.

As another example, here's a little mind-reading trick.  Which number comes next in the series 2-4-6-8....?  Quick! What's your answer! Ten? Sorry, but you did not read my mind. I was thinking of the number ... nine. You automatically assumed that I generated the numbers in this series on the basis of increasing even numbers, or a number plus two more. However, my rule, the one that you didn't think of, is "increasing numbers." You concluded the increase had to be by two, but there is nothing about an increase of one that would make my answer wrong. I have given this simple problem to each of my introductory psychology classes (of about 500 students each) for about 10 years, and almost no one guesses nine.  If you groaned when you heard my answer, don't worry, all of them do too.

The increasing numbers problem is another instance of the so-called "confirmation bias" that leads us to avoid seeking to disconfirm our hunches.  We rarely seek to prove ourselves wrong. Yet, being able to find disconfirmation is just as, if not more, important than seeking confirmation. 

Trying to prove yourself wrong is one of life's most valuable skills and can definitely save you money.  For example, consider what happens when you're about to make an investment or a major purchase.  Anticipating the pleasures or gains associated with this outlay turn the switch to "on" in the reward circuits in your brain. We anticipate with pleasure the desired outcomes we will receive, feelings that continue to build on themselves. As they do, the logical voices seeking disconfirmation become quieter and quieter.  If you don't stop the process in its tracks and contemplate what will happen if you're wrong, you may be making a costly mistake.

Looking for disconfirmation may also save you social embarrassment. Maybe you shouldn't wear that sweater which is just a bit too loud, tight, or just plain wrong for you.  Having bought it, kept it, and planned to put it on, it's going to be very hard for you to take that extra look in the mirror before you leave the house and switch it for one that isn't fatally flawed. It's not that you need to over-think every decision that you make, no matter how trivial.  But it is wise to pause and perform a small reality check especially if you have a secret hunch that you may be making a poor choice.

Think now about what happens when you're trying to repair something that's broken-- a favorite gadget or your beloved PC (or Mac).  Perhaps you've got a jar that just won't open. You start in on one strategy, but it doesn't work. It's time to stop and reboot your brain. However, most people will just persist in the strategy they began on, even if it's not producing results. This tendency, called "functional fixedness," is another variant of the cognitive processes that produce the confirmation bias. In functional fixedness, we pursue a problem-solving strategy that's not appropriate for the current situation because it worked in the past. Instead, we need to break set, meaning get a fresh perspective. Think outside the box. Stop, take a look at that broken object or stuck jar, and see if you can get at the solution from another angle. Continuing to pursue a problem-solving strategy that isn't producing results will not only lead to failure, but frustration and stress. Get over it by getting over your mental set.

Seeking disconfirmation is also helpful in a wide variety of social situations.  According to social psychologists, we fall prey to the "assumed similarity bias" when we judge other people. The assumed similarity biase causes us to think: "I feel this way, so you must feel this way." We impose our own values, beliefs, perceptions, and judgments onto others without realizing that not everyone sees the world the same way that we do.

Test-takers are known suckers for the confirmation bias. When faced with a set of choices, people who are unsure of an answer will come up with a hunch. Once they've done that, they find it very difficult to see any other possible solutions. The same situation happens in work settings. You're trying to find the right formula, product, or strategy and if you're not careful, the first one that pops into your head is the one you will stick with, no matter what. In test-taking situations, people often remember (incorrectly) the times that they changed their first (right) answer to the wrong one. They use this as justification never to change their first answers in the future. However, as I pointed out in an earlier posting, this "instinct fallacy" can lead people to avoid the more common situation requiring that you re-read questions to make sure your first hunch was in fact the correct one.

I hope you agree with me that the Wason task has important life consequences. Learning to look at life "from both sides" can help you make more logical and fulfilling decisions.

If you enjoyed learning about the Wason task, there are several excellent web resources, including these well-crafted "Philosophy Experiments" and "All Fun and Games."

Follow me on Twitter @swhitbo for daily updates on psychology, health, and aging. Feel free to join my Facebook group, "Fulfillment at Any Age," to discuss today's blog, or to ask further questions about this posting.

Copyright Susan Krauss Whitbourne, Ph.D. 2012